The legal system in its broadest sense functions best when persons in need of legal
advice or assistance are represented by their own counsel. For this reason a lawyer should
not communicate on the subject matter of the representation of his client with a person he
knows to be represented in the matter by a lawyer, unless pursuant to law or rule of court
or unless he has counsel, a lawyer representing another may have to deal directly with the
unrepresented person; in such an instance, a lawyer should not undertake to give advice to
the person who is attempting to represent himself, except that he may advise him to
obtain.